1. Field of the Invention
This invention relates to three wheeled vehicles and, more particularly, to apparatus for centering the front wheel and in which the front wheel may be the driving wheel.
2. Description of the Prior Art
U.S. Pat. No. 90,687 (Rathmann & Johnson) discloses a bicycle with front wheel drive. The front wheel drive is hand cranked. The rear wheel is the steering wheel.
U.S. Pat. No. 92,689 (Atherton) discloses a hand cranked three wheeled vehicle with provisions for two passengers, the front passenger of which uses foot cranks connected to the front wheel, and the second, rear, passenger uses hand cranks connected to the rear wheel. Steering is through the front wheel.
U.S. Pat. No. 201,179 (Higley) discloses a three wheeled vehicle with provisions for both foot crank and hand crank elements connected to the front wheel. The front wheel is both the driving wheel and the steering wheel.
U.S. Pat. No. 505,373 (Sanford) discloses a three wheeled vehicle with hand crank elements connected to the front wheel. The front wheel is used for both driving and steering.
U.S. Pat. No. 577,749 (Hayes and Dilley) discloses a conventional chain drive for a bicycle. The chain drive is connected through pedals to the rear wheel. A tension spring is connected between the frame and the front forks for centering the front wheel. The centering apparatus is an add-on feature that may be used for virtually any model of bicycle.
U.S. Pat. No. 606,525 (Dunning & Barrow) discloses a pair of springs which act as torsion springs on a front fork spindle of a bicycle for urging the front wheel to a centered, straight ahead, position.
U.S. Pat. No. 1,873,047 (Schimmel et al) discloses a three wheeled vehicle which utilizes a hand crank connected to the front wheel through a chain drive. The front wheel is used for both steering and driving.
U.S. Pat. No. 3,848,891 (Vittori) discloses a three wheeled vehicle in which a front wheel is driven by a hand crank system. The hand crank system is unique in that it may be either a strictly a chain drive system through a pair of chains or a rotating shaft through a gear system may be connected to a chain drive. In other words, there are two drive elements between the hand crank and the front wheel, rather than the single chain drive system in the hand crank patents discussed above in conjunction with front wheel drive apparatus. Similarly, there are two connections for the front wheel, a standard pair of forks which connect the front wheel to the frame of the vehicle, and a second pair of forks utilized in conjunction with the driving system for the front wheel.
U.S. Pat. No. 4,720,117 (Hay) discloses apparatus for converting a wheel chair into a three wheeled velocipede. A pair of parallel links connect a frame to the front wheel which is a driving wheel powered by hand cranks. The pair of links is pivotly secured to a frame which is in turn secured to the wheel chair.
U.S. Pat. No. 5,022,671 (Jones) discloses a three wheeled velocipede powered by a hand crank system and utilizing a chain drive. A pair of springs is used to help center the front wheel fork relative to the frame. The springs are tension springs secured to a bar which is in turn secured to the front forks and is generally perpendicular to the front forks.
Most of the above discussed patents are three wheeled vehicles, or relate to three wheeled vehicles. Also, most of the above discussed patents utilize hand crank mechanisms connected to a front drive wheel. A few of the patents disclose elements for helping to center the front wheel when the front wheel is the driving wheel. Typically, springs are used. In one case, a pair of springs is used, and in another case a single tension spring is used as an add-on feature.
The apparatus of the present invention utilizes a tension spring to help center the front wheel of a three wheeled vehicle in which the front wheel is the driving wheel, being driven through a hand crank system.